In recent years, LEDs, which have a long life and a small power consumption, have come into common use as backlights of liquid crystal display devices and light sources of illumination equipment. In such a light source, a desired luminescent color is obtained by combining LEDs of a plurality of different luminescent colors, by combining monochromatic LEDs and a phosphor, or the like. For example, a white LED is generally formed by combining a blue LED with a phosphor. In such a white LED, white light is obtained by combining the colors of the blue light which is emitted from the blue LED chip and the light which is emitted due to the phosphor being excited by the blue light.
A direct backlight or an edge light backlight is applied in order to use such a white LED in a backlight. In the direct backlight, each white LED radiates direct light onto the rear surface of a liquid crystal panel. Meanwhile, in the edge light backlight, the light of white LEDs is incident from the side end portion of a light guide plate, the light is emitted from the exit surface of the light guide plate, and is radiated onto the rear surface of the liquid crystal panel.
Of these, in the edge light backlight, since, ordinarily, the plurality of white LEDs is disposed on the side end portion of the light guide plate, it is easy to reduce the thickness. Therefore, for example, in order to simplify the embedding of white LEDs in a liquid crystal display device, the white LEDs are installed in a state of being disposed in a straight line along the side end portion of the light guide plate, and are provided as a straight line shaped light source (for example, PTL 1 and 2).
There is an illumination equipment in which the light from multiple LEDs is converted into planar light by a light guide plate and radiated in order to illuminate a comparatively wide space, as in a ceiling light. In such illumination equipment, a light source in which a plurality of LEDs is disposed to line up in a straight line on a substrate is provided so as to allow the light from the LEDs to enter a light entrance portion of the light guide plate (for example, PTL 3). In such illumination equipment, although illumination light of a desired color is obtained by mixing the colors of light from LEDs of a plurality of different luminescent colors, there is an illumination equipment which has a function of adjusting the color of the illumination light by adjusting the luminescent color of each of the LEDs.